#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>

long unsigned countInner;

char *sfmtTime(char *buf, struct timeval tv) {
  char *tstr;
  tstr = ctime(&tv.tv_sec);
  if (tstr != NULL) {
    int tslen;
    tslen = strlen(tstr);
    if (tstr[tslen-1] == '\n')
      tstr[tslen-1] = 0;
    sprintf(buf, "%s + %06ldus", tstr, (long) tv.tv_usec);
  } else sprintf(buf, "%ld + %06ldus (ctime failed)",
		 (long) tv.tv_sec, (long) tv.tv_usec);
  return buf;
}

long dtv(struct timeval tva, struct timeval tvb) {
  long ds  = tva.tv_sec  - tvb.tv_sec ;
  long dus = tva.tv_usec - tvb.tv_usec;
  return (dus + (1000000*ds));
}

void inner() {
  int i;
  for (i = 0; i < 10000000; i++)
    countInner ++;
  return;
}

int main(int argc, char **argv) {
  long unsigned countOuter, lastCount = 0;
  struct timeval tva, tvb;
  int res, ReportPeriod_S, ReportPeriod_US;
  long since;
  char buft[100];
  if (argc != 2) {
    fprintf(stderr, "Usage: %s report-period\n", argv[0]);
    return 1;
  }
  ReportPeriod_S = atoi(argv[1]);
  ReportPeriod_US = ReportPeriod_S * 1000 * 1000;
  fprintf(stdout, "Report Period = %g seconds\n",
	  ReportPeriod_US/(double)1.0e6);
  res = gettimeofday(&tva, NULL);
  if (res != 0)
    exit(22);
  for (countOuter = 0; ; countOuter++) {
    inner();
    res = gettimeofday(&tvb, NULL);
    if (res != 0)
      exit(22);
    since = dtv(tvb, tva);
    if (since > ReportPeriod_US) {
      long unsigned dCount = countOuter - lastCount;
      float rate = dCount * 1.0e6 / since;
      printf("At %s, count=%lu,\n"
	     "d-count=%lu, d-t=%ld us, rate=%4.2f/s\n",
	     sfmtTime(buft, tvb),
	     countOuter,
	     dCount,
	     since,
	     rate);
      lastCount = countOuter;
      tva = tvb;
    }
  }
}